Among the first "lemons" (or proto-lemons) that appeared in Italy, there were a few pomelo-citron hybrids. This perhaps could be such a hybrid that then got crossed with a regular lemon (citron x sour orange). There was all sorts of hybridization going on in Italy. Lemons got backcrossed with citron again to form new lemons. Italy has the most lemon varieties in the world.

Hey there,Lumia is another of those words that has a strange story and doesn't seems to refer to a specific lemon clone.This paper is in italian but abstract is english so maybe you can find here something interesting.http://www.quadernibotanicambientaleappl.it/quaderni/26_043-050.pdfTo enter more in details on the text of the paper, they report that the word "lumias" (the final s was due the fact the word was in latin) has been used firstly in 1169 by Falcando to describe lemons and later by other expert in citrus to describe citronsXorange hybrids (i think this is the name which sitcked with common folks here). In Ferrarius (1646) in Capitulo XXVI, page 333, the lumias are described as "Limon, qui dicitur lumia" ("Lemons, which are called lumias". Basically it looks like at such age lemons and limes weren't perceived as different entities; so lemons were the common lemons, limettas were the acid limes, while lumias were the acidless limes. Of course, since they were considered lemons, some confusion may have arised. Candolle, in 1885, assumed that both lumias and limes where the same stuff and united both under the name citrus limetta. Since lumias was a word referred to several lemon like clones, i guess that some clones have retained the folk's name "lumias"; even when the official taxonomy gave the name "lumia" only to acidless limes. That must be the case for the pear shaped lemons.

Also, lumias referring to both those pear shaped lemon and acidless limes must be the reason behind:https://citrusvariety.ucr.edu/citrus/lumia.htmllisting lumias as "acidless" but after tasting it they reported "this is not acidless at all!".Basically they assumed that lumia meant what it means in scientific literature. Probably they look to import for lumia and got a lumia: but not the one with such scientific name, rather just one of the pear shaped lemons commonly referred by citrus growers here as "lumia". Which surely are not acidless!In sicily instead lumia refers to plants very similar to palestine sweet lime.

Radoslav what book are you referring to? The 1982 book on citrus paintings by CNR?

Ancient persian cultivar Lumia Adam's apple, (d'Adam, du Paradis, Pomme d'Adam, Pomme du Paradis, Pomo d'Adamo ), was described by Marco Polo, later during crusade by Jacques de Vitry and later by authors which I mentioned above.

Ok i was thinking you were referring to this one:Wich has a good list of ancient italian cultivar, and it's pretty interesting for those wich are interested to this topic. Some of the stuff here is weird, and now has gone extinct basically for sure (like for instance the lemon which was 100% albedo).